Unit 51
Big Creek
High-elevation pronghorn country straddling the Wyoming-Colorado line with rugged mountain terrain and limited water.
Hunter's Brief
Unit 51 sits along the North Platte and Encampment Rivers at the Wyoming-Colorado border, featuring medium elevation terrain that transitions between open parks and moderate forest cover. Access is limited with roughly 130 miles of roads spread across mixed country—expect some rough going but solid terrain for glassing. Water sources are scattered through reservoirs, ditches, and creeks, making water strategy important. The unit runs complex terrain with adequate room to escape pressure if you're willing to work for it.
- Compact: under 200 sq mi
- Moderate: 200 - 800 sq mi
- Vast: over 800 sq mi
- Few: under 25%
- Some: 25 - 60%
- Most: over 60%
- Limited: under 0.7 mi/mi² (backcountry)
- Fair: 0.7 - 1.5 mi/mi²
- Connected: over 1.5 mi/mi² (well-roaded)
- Flat: under 20% mountains
- Rolling: 20 - 55%
- Steep: over 55%
- Sparse: under 20%
- Moderate: 20 - 50%
- Dense: over 50%
- Limited: under 0.3% area
- Moderate: 0.3 - 2% area
- Abundant: over 2% area
Terrain Deep Dive
Landmarks & Navigation
Prospect Mountain and Bennett Peak anchor the upper terrain and serve as key reference points for navigation across the expansive parks. The Encampment River corridor provides the most obvious linear navigation feature, with East Fork Encampment, Cherokee Creek, and Miller Creek draining major valleys. The scattered reservoir system—Thompson, Lordier, Toothaker, and Golden Clover—marks reliable water and potential camp locations.
Commissary Park, Beaver Dam Park, and Cunningham Park represent the largest open flats ideal for glassing pronghorn across sagebrush country.
Elevation & Habitat
The unit spans medium-elevation country from roughly 7,000 feet to just under 11,000 feet, with most terrain sitting in the 8,000-foot range. This elevation band supports a mix of open parks and moderate forest coverage—sagebrush flats punctuated by stands of ponderosa pine and scattered higher-elevation timber. The parks and parkland dominate the usable pronghorn habitat, with numerous named flats offering glassing opportunities and movement corridors.
Forest remains moderate enough to navigate but thick enough in places to create cover and complexity.
Access & Pressure
Limited road density and rough mountain terrain keep overall pressure moderate, though existing access concentrates hunters along the river corridors and established ranch roads. The 130 miles of roads mean intelligent routing is key—most casual traffic follows obvious drainages and park entrances. The complexity of terrain (7/10) suggests hunters willing to move beyond roadside glassing can find quieter country.
Private land interspersed through ranching areas likely controls some access, so prior scouting and landowner contact matter significantly.
Boundaries & Context
Unit 51 follows a distinctive triangle formed by the North Platte River on the east and south, the Wyoming-Colorado state line on the south and west, and the Encampment River running northeast to anchor the northern boundary. The unit sits at the transition zone between Colorado's mountains and Wyoming's high plains, placing it in rugged foothills country with significant elevation relief. This location along two major river corridors creates natural travel routes but also defines access points and potential bottlenecks for hunters moving through the terrain.
Water & Drainages
Water is limited but structured around key features. The North Platte and Encampment Rivers provide seasonal flows along the boundaries, while the East Fork Encampment River cuts through the unit's interior. A network of smaller creeks—Miller, Cascade, Jordan, Miner—and springs offer supplemental sources.
The reservoir system (Thompson, Lordier, Toothaker, Golden Clover, Brownlee) and extensive ditch infrastructure suggest irrigation-dependent water access. During dry periods, these reservoirs and known springs like Rock Springs become critical for both hunting logistics and understanding where pronghorn concentrate.
Hunting Strategy
Unit 51 is pronghorn country defined by open parks and sagebrush flats at medium elevation. The habitat supports resident and migratory pronghorn populations that use the parks for feeding and the creeks for water access. Early season hunting focuses on glass-and-stalk tactics across the flats before animals shift with weather and hunting pressure.
The river corridors and creek bottoms provide natural ambush points for routing herds during mid-season movement. Water becomes increasingly important as the season progresses, making reservoir and spring locations key to finding animals in the dry months.